1. Field of the Invention
The present invention relates to a feces sampling container for use in assaying feces as a specimen, and a method and analyzer for assaying feces.
2. Description of the Background Art
Heretofore, there has been known a feces sampling container, or a container for sampling feces as a specimen, as disclosed, for example, in the following Patent Publications 1 to 4:
[Patent Publication 1] Japanese Patent Laid-Open Publication No. 10-257881;
[Patent Publication 2] Japanese Patent Laid-Open Publication No. 2001-183362;
[Patent Publication 3] Japanese Patent Laid-Open Publication No. 10-160728; and
[Patent Publication 4] Japanese Patent Laid-Open Publication No. 2000-258308.
This type of feces sampling container comprises a feces sampling instrument, and a container body containing a feces-dissolving liquid, wherein the feces sampling instrument with feces attached thereon is immersed in the feces-dissolving liquid so as to disperse the feces over the feces-dissolving liquid to form a suspension. In a quantitative analysis of a component (e.g. hemoglobin) of feces using this type of feces sampling container, a certain amount of the suspension in the container body is extracted by a nozzle of an automatic analyzer from the upper side of the container body in a suction manner, and the extracted suspension is analyzed after diluted.
However, when the above quantitative analysis is performed using the conventional feces sampling containers as disclosed in Patent Publications 1 to 4, the automatic analyzer fails to extract an intended amount of the suspension in some cases.
For example, one factor of the failure is associated with the need for re-assay of the suspension. Specifically, in the above automatic analyzer, a particular result of the analysis may require a re-assay for the same suspension. In this case, the liquid level of the suspension in the feces sampling container will be inevitably lowered every time the re-assay is repeated. Thus, when the liquid level of the suspension is lowered beyond the position of a suction port of the nozzle due to repetition of the re-assay, the nozzle becomes unable to suck the suspension, which leads to deficiency in extraction amount of the suspension, or no extraction of the suspension in the worst case.
Another factor of the failure is associated with clogging of the nozzle of the above automatic analyzer. Specifically, the automatic analyzer is designed to introduce the nozzle into the suspension, and extract the suspension in a suction manner. Thus, if a relatively large agglomeration of feces or insoluble substance is contained in the suspension, the nozzle can be clogged therewith to hinder sucking the suspension in an intended amount.
While Patent Publications 3 and 4 disclose a container body which further includes a filter for filtering the suspension, and contains the filter in such a manner as to allow the suspension passing through the filter to be sucked by the nozzle, even this container cannot avoid the problems about deficiency in extraction amount of the suspension due to repetition of the re-assay.
The above built-in filter type container is designed to dispose the filter in such a manner as to be in contact with the feces-dissolving liquid in advance, and to assay the filtered suspension. This involves a risk that the concentration of an analyte in the filtered suspension is lowered by the feces-dissolving liquid pre-infiltrated in the filter.
In the conventional feces sampling container, if an intended amount of the suspension cannot be extracted from the feces sampling container for the above reasons, the extracted suspension will be directly diluted and without any recognition of the above fact, and the diluted suspension having a undesirable lowered concentration will be assayed, which is likely to result in a wrong assay result.